Meanwhile, I cleared out the old MacBook and loaded a new version of Catalina. I opened DiskUtility and there it was, greyed out with no access. I plugged in the hard drive and it just sat there steadily flashing the light. Long story short one of the programs I use regularly wasn't ready for Big Sur so I attempted to go back to Catalina. I had the old one enrolled in the beta program so of course after moving to the new one it was too. I used the hard drive to transition from the old one to the new one. I also have 2 MacBook Airs, one mid 2013 and one less than a month old.
I've got a WD My Passport 1TB SSD external drive.
